constarray=['🍝','🍜','🍲'];constnotArray='not array';_.isArray(array);// true_.isArray(notArray);// false Yes, the syntax is the same as Lodash 🤓 #Why can't we usetypeof? Often, we want to check the type of a value, we simply usetypeof ...
Checking if a variable is an array in JavaScript is one of the most common tasks you may encounter while building a Javascript-based application. There are several ways to perform this check, each with its pros and cons. In this post, we'll review three ways to determine if a variable ...
To check if a JavaScript array is empty or not, you can make either of the following checks (depending on your use case): const empty = !Array.isArray(array) || !array.length; const notEmpty = Array.isArray(array
If you try to access an element of an array that hasn’t been initialized, it returns undefined. Here’s an example of the code. let numbers = [1, 2]; console.log(numbers[3]); // undefined Read More: Common JavaScript Issues and its Solutions Methods to check if a Variable is Un...
Topic: JavaScript / jQueryPrev|NextAnswer: Use the indexOf() MethodYou can use the indexOf() method to check whether a given value or element exists in an array or not. The indexOf() method returns the index of the element inside the array if it is found, and returns -1 if ...
//code to check if a value exists in an array using javascript indexOf var fruits_arr = ['Apple', 'Mango', 'Grapes', 'Orange', 'Fig', 'Cherry']; var string = "Orange"; // Find in Array fruits_arr.indexOf('Tomato'); fruits_arr.indexOf('Grapes'); // Find in String string...
Object.prototype.toString.call(variable) === '[object Array]'; This guy is the slowest for trying to check for an Array. However, this is a one stop shop for any type you're looking for. However, since you're looking for an array, just use the fastest method above. ...
This guy is the slowest for trying to check for an Array. However, this is a one stop shop for any type you're looking for. However, since you're looking for an array, just use the fastest method above. Also, I ran some test: So have some fun and check it out....
In the example above, theindexOf()method returns the index of “banana” in the fruits array, which is 1. If we were to check for a value that does not exist in the array, such as “grape”, the method would return -1. letfruits=["apple","banana","orange"];letindex=fruits.inde...
To clear an array in JavaScript, you can assign a new empty array "[]" to it or set the length of the array to zero (array.length = 0). The first way is the fastest, and it's handy if you don't have references to the original array anywhere else because it creates a whole ne...